The present invention relates to quality control in connection with photographic pictures.
More particularly, the invention relates to a method of controlling the quality of photographic pictures during taking of the pictures and/or during printing of the pictures.
The invention also relates to apparatus for carrying out the method.
It is well known that various error sources exist which may lead to unsatisfactory photograhic pictures, during the actual picture-taking and/or during subsequent printing of the paper pictures. Until now, the consumer has had no way of determining exactly where such errors have occurred, i.e. who (or what) may be at fault.
Exposure and color errors can largely be compensated during developing and/or printing and therefore present no problem of great magnitude. However, such corrections are not possible when a picture is out of focus, at least not where amateur photography is concerned. The only real solution here is to eliminate the error source--but to do this it is necessary to locate the error source, which was not heretofore readily possible.
The difficulty is that a lack of sharpness can be caused by a variety of circumstances. It may be due to the consumer's own error in moving the camera while taking a picture or in improperly focussing the lens. It may also be due to rapid movement of the object being photographed. However, the problem can equally well be caused by a faulty lens or by the film not being located completely planar opposite the film window; in some instances the source of error may reside with the maker of the camera and/or the film. Then again, the film may not have been properly inserted into the camera or it may have been stored in the same for too long a period of time.
Other error possibilities have to do with film handling by the photo-finisher, i.e., the laboratory where the film is developed and printed. The printer may be defocussed during making of the paper pictures, the transportation and exposure phases may overlap in the printer, or the film and/or photographic paper may not be in proper planar position during printing.
Evidently, pin-pointing the error source is of importance here. If the error was made by the photo-finisher, then the consumer can after all obtain a useful picture simply by requesting that a new print be made. If the error has occurred while the film was still in the camera, i.e., during the picture-taking phase, it can evidently not be corrected by making a new print--a second print would be as poor as the first one and, even if it is furnished free of charge, this will lead to a certain degree of customer dissatisfaction.
It is therefore desirable for the consumer to be able to determine in a simple manner and without detailed analysis of the photographic negative and of the positive picture, whether the error causing the unsharp condition has occurred in the camera or during processing by the photo-finisher.